TWO NEW NEOTROPICAL SPECIES OF THE SUBGENUS ISOHELEA OF BRACHYPOGON ,WITH THE DESCRIPTION Of THE FEMALE OF B. ( l .) MISIONENSIS AND A KEY TO THE NEOTROPICAL SPECIES (DIPTERA: CERATOPOGONIDAE)

8 Pages·1994·0.58 MB·

by  Spinelli, Gustavo R

Rev. Soco Eniomol. Argent. 53 (1··4):1-8, 1994
TWO NEW NEOTROPICAL SPECIES OF THE SUBGENUS ISOHELEA
Of BRACHYPOGON,WITH THE DESCRIPTION Of THE FEMALE OF B.
(l.) MISIO NSIESN ANO A KEY TO THE NEOTROPICAL SPECIES
(D IPTERA: CDERATOPOGONI AE)
SPINELLI, Gustavo R.* & William L. GROGAN, Jr.**
ABSTRACT. Brachypogon (Isohelea) hugoifrom Colombiaand B.(I.) pallidipennis
from Honduras are described and illustrated as new species. The female of
Brachypogon (Isohelea) misionensis Spinelli, from Brazil,is described and
illustrated, and a key is presented for the recognition of the five Neotropical
species of Brachypogon (Isohelea).
RESUMEN.Dosespeciesnuevasneotropicales de Brachypogon(Isohelea), con
la descripción de la hembra de B. (I .) misionensis y clave para las especies
neotropicales (Diptera: Ceratopogonidae). Sedescriben e ilustran dos especies
nuevas, Brachypogon (hlso el ea) hugoide Colombia, y B.(l.) pallidipennis de Hon
duras, asícomo la hembra de Brachypogon (lIsoheea ) misionensis Spinelli del Bra
sil. Además, se incluye una clave para el reconocimiento de las cinco especies
neotropicales de Brachypogon (Isohelea).
The small predaceous midges of the subgenus Isohelea of Brachypogon Kieffer
are apparentlypoorly represented in the NeotropicalRegion,comparedwith the other
biogeographic regions of the world (Wirth & Grogan, 1988). The three known
Neotropicalspecies, B. misionensis. B.mapuche, and B.toirthi, were recenUy described
by Spinelli (1990) from Argentina. Borkent (1992) and Grogan & Borkent (1992)
demonstrated that Brachypogon and four other genera, Ceraioculicoides, Nannohelea,
Rhynchohelea and Sinltalohelea, share the synapomorphyof possessing at leastonelarge
katepisternal seta.
During taxonomic studies of Brachypogon and related genera of the tribe
Ceratopogonini,weencountered twoundescribedspeciesof thesubgenus Isolzelea and
thepreviouslyunknownfemale of B.(I.)misionensis in materialhoused at theNational
Museum of Natural History, Washington, D. C. (USA). We describe these species
herein and provide a key for the recognition of the five Neotropical species of
Brachypogon (lsohelea).
For general ceratopogonid terminology see Downes & Wirth (1981); for
a diagnosis and special terms dea]¡¡ll11g with Brachypog@l1 see Wirth & Grogan
(1988).
*Instituto deLisnnologia "Dr. Raúl A.Ringuelet", Casillade Correo712, 1900 La Plata, Argenti
na.
**DepartamentofBiolegical Sciences,SalisburyStateUniversity,Salisbury,Maryland21801,USA.
2 Rev. Soco Eniomol. Argent.53 (1-4), 1994
Key to the Neotropical species of Brachypogon (Isohelea)
1. Females , 2
Males 6
2. One spermatheca 3
Two spermathecae 4
3. Large species, wing length 0.97-1.03 mm; wing membrane infuscated with2 well
developed radial cells and macrotrichia present in margin of cell cual and anal
cell; halter whitish; spermatheca with conical neck B.hugoi sp. n.
Smaller species, wing length0.74 mm; wing membrane hyaline, 2nd radial cell
minute, macrotrichia absent in margin of cell cual and anal cell; halter dark
brown; spermatheca with narrow neck B. mapucheSpinelli
4. Wing membrane infuscated, vein M2 present, macrotrichia absent in margin of
cell cual and anal cell; antennal ratio 1.18 B. misionensis Spinelli
Wingmembranewhitishhyaline,vein M2 absent, macrotrichiapresentinmargin
of cell cual and anal cell; antennal ratio 0.93-0.98 5
5. Radial cells of wing equal sized, stigma yellowish; spermathecae equal sized,
ovoid B.toirthi Spinelli
Second radial cell of wing minute, stigma pale brown; spermathecae unequal,
obliquely ovoid B. pallidipennis sp. n.
6. Tergite 9 with circular or quadrate sclerotized area on ventrodistal portion;
aedeagus with bilobed apex 7
Tergite 9 lacking ventrodistal sclerotized area; aedeagus without bilobed
apex 8
7. Sternite9withnarrow, truncate,posteriormargin; tergite9withnarrowsclerotized
band on ventrodistal portion; basal arm of aedeagus long ..
......................................................................................................... B.misionensis Spinelli
Sternite 9 with broad, irregular, posterior margin; tergite 9 with large quadrate
sclerotized area on distal portion; basal arm of aedeagus short....B.hugoi sp. n.
8. Gonocoxite1.5XlongerthanbroadwithoutstoutsetaedistalIy;gonostylusslender
withpointedtip,surfacesmooth;aedeaguswithtruncateapex, withoutadditional
processes; parameres elongate, 2.5 X longer than broad, distal portion divided
with slender abruptly recurved extensions B. mapucheSpinelli
Gonocoxite stoutwith 12 strongsetae distally; gonostylus stoutwith bilobed tip,
surface irregular; aedeagus with sublateral, distomedian and laterally directed
processes; parameres shorter than broad, distal portion with truncate apex .......
...........................................................................................................B.pallidipennissp. n.
Brachypogon (Isohelea) hugoi sp. n.
(Figs. 1-6)
Diagnosis. Distinguished from all other Neotropical species of Brachypogon
(Isohelea) by thefollowingcombinationofcharacters:wingwithinfuscatedmembrane,
stigmaandveinsdarkbrown;2welldeveloped radialcells;vein M2 poorlydeveloped
SPINELLI,C.R. &W. L.GROGAN,Jr., Brachypogon 3
1
6
Figs. 1-6. Brachypogon (lsohelea)hugoi. 1, female flagellum; 2, female palpus; 3, female wing; 4,
spermatheca;5, male genitalia, aedeagus removed; 6, aedeagus.
4 Rev. Soc.Entomol. Argent.53 (1-4), 1994
distally;male tergite9with quadrateheavilysclerotizedareaventrodistally;aedeagus
with shortbasal arm, apex bilobed; female with one ovoid spermatheca, with conical
neck; claws moderately large, unequal, the smaller talon of each bears a long basal
inner tooth; and macrotrichia present in cell cual and anal cell of wing.
Female. Wing length 0.97-1.03 mm; breadth 0.46-0.48 mm. Head dark brown.
Eyes narrowly contiguous, pubescent. Scape of antenna with four setae; flagellum
(Fig. 1) uniformly dark brown, lengths of flagellomeres in proportion of 25-14-14-11
12-13-13-·14-28-28-28-23-30; antennal ratio 1.18 (n =2);flagellomere 1with two apical
sensilla coeloconica. Palpus (Fig. 2) dark brown, lengths of segments in proportion
of 15-26-36-20-30;segment3 with a distal round sensorypit, palpal ratio 2.00 (n = 2);
segment 4 with two large setae. Mandible with 10-11 teeth. Thorax dark brown; five
prealar setae; one katepisternal seta; scutellum with two marginal and one central
setae. Femora and tibiaeslender, hind femur broadest; hind tibia with comb of seven
setae, apical spur bifid; hind tarsal ratio 2.20 (n = 2); tarsomeres 4 cordiform;
tarsomeres 5 with moderately large unequal claws, the smaller talon of each bears a
long basal inner tooth, lengths of fore, mid and hind claws in proportion of 17:12,
17:12, 19:12. Wing (Fig. 3) membrane infuscated, stigma and veins dark brown,
membrane covered with coarse microtrichia, macrotrichia restricted to margin, costa
and base and near apex of radius; two radial cells, 1st larger; r-m crossvein oblique;
MI and cubital fork obsolete at apices near wing margin, M2 poorIy developed
distally; costal ratio 0.56-0.58 (n = 2). Halter whitish. Abdomen dark brown. Sternite
10 with one pair of large setae. One ovoid spermatheca (Fig. 4), with stout conical
neck, measuring 0.064x 0.041 mm.
Male. Similar to female with the following notable sexual differences. Eyes
narrowlyseparated. Flagellomeres2-11fused. Mandiblereduced,vestigial.Tarsomeres
4 cylindrical; claws small, simple with bent bifid tips. Wing narrower; wing length
1.05 mm, breadth 0.41 mm; membrane lacking macrotrichia; radial cells equal sized;
costal ratio 0.47. Genitalia as in Figs. 5-6. Sternite 9 moderately short, with irregular
caudal margin; tergite 9 tapering distally to a truncate posterior margin, ventrodistal
portion with large quadrate heavily sclerotized area, the anterior margin of which
contacts the posteriorportion of parameres, apicolateral processes short, cerci small.
Gonocoxite stout, with a short,blunt, mesobasallobe; gonostylus short, stout, nearIy
straight, tip pointed.Aedeagus(Fig.6)stout,light1y sclerotizedexceptfor twopointed,
posteromesally-directed processes; basal arch very low, rounded; apex bilobed.
Parameresfused; composedof twonearly parallelsidedheavilysclerotized processes
joined by a more lightly sclerotized bando
Distribution. Colombia, known only from the type-locality.
Types. Holotype male, allotype female, and 4 paratypes (1 female, 3 males),
labeled"Colombia,Narino,20mi EPasto, 1-II!.1955,Schlinger& Ross". The holotype
and allotype are deposited in the California Academy of Sciences, San Francisco
(CASC); 1maleand1female are depositedin theNationalMuseumofNaturalHistory
(NMNH); 1 male deposited in the Museo de La Plata, Argentina (MPLA); and 1
deposited in the Canadian National Collection of Insects, Ottawa (CNCI).
Etimology. This species isnamed in memoryof the seniorauthor's dearfriend,
Hugo R. Amoreo.
Discussion. Brachypogon (lsohelea) mapucheis theonlyotherNeotropical species
of the subgenus Isohelea withasinglespermatheca. Femalesof thisspeciesdifferfrom
SPINELLI,G.R. & W. L. GROGAN,Jr., Brachypogon 5
this new species because the neck of its spermatheca is narrower, it is smaller (wing
length 0.74 mm), both talons of its claws have basal inner teeth, its wing membrane
is hyaline, the second radial cell is minute, macrotrichia are absent in cell cual and
anal cell and the halter is whitish. The only other Neotropicalspeciesof the subgenus
Isohelea with a bilobed apex on its aedeagus andbearing a heavily sclerotized area on
the ventrodistal portion of tergite 9 is B. (I.) mieionensis. Males of this species differ
from those of this new species by the long basal arms on its aedeagus; sternite 9 is
narrow with a truncate posterior margin, and the heavily sclerotized area on the
ventrodistal portion of tergite 9 is circular, not quadrate.
Brachypogon (lsohelea) misionensis Spinelli
(Figs. 7-10)
Brachypogon (Isohelea) misionensisSpinelli, 1990: 752 (male; Argentina; figs.).
Diagnosis. Distinguished from all other Neotropical species of Brachypogon
(Isohelea) by the following combination of characters: wing membrane infuscated,
stigmaand anteriorveins darkbrown: two radialcells;vein M2 present; male sternite
9narrow, posterior margin truncate; tergite 9with a circular, heavily sclerotized area
ventrodistally; aedeagus basal arm long, apex bilobed; female with two obliquely
ovoid spermathecae; claws moderately large, subequal, with basal inner teeth; and
macrotrichia present in margin ofcells R5, M1, and M2.
Female.Winglength0.94 mm;breadth0.44 mm. Head darkbrown. Eyesbroadly
contiguous, pubescent. Antennal scape with five setae; flagellum (Fig. 7) withlengths
of flagellomeres in proportionof 26-14-14-16-18-18-18-18-30-32-32-28-34;antennalratio
1.10; flagellomere 1 with 3 apical sensilla coeloconica. Palpus (Fig. 8) with lengths of
segmentsinproportion of 14-28-35-20-22;segment3with deep subapical sensory pit,
palpal ratio 1.60; segment4with two large setae. Mandible with 8 teeth. Thorax dark
Figs. 7-10. Brachypogon (Isohelea) misionensis, female. 7, flagellum; 8, palpus; 9, wing; 10,
spermathecae.
6 Rev.Soco Entomol.Argent. 53 (1-4), 1994
brown; five prealar setae; two katepisternal setae; scutel1um with two marginal and
twocentralsetae. Femoraand tibiaeslender;hind tibiawithcombofsevensetae,apical
spurshort;tarsiexcepttarsomeres5lightbrown,hind tarsomere1withwel1developed
palisade setae, hind tarsal ratio 2.00; tarsomeres 4 subcylindrical; tarsomeres 5 with
moderatelylargesubequalclawswithbasalinnerteeth, lengthsof fore, mid and hind
clawsin proportionof 17:12,20:12,20:12,.Wing(Fig. 9)membraneinfuscated,stigma
and veins dark brown; membrane covered with coarse microtrichia, macrotrichia
presentonly on margin of cel1sR5, MI, M2 and at base and near apex of radius; two
radial cells, 2nd minute; r-m crossvein oblique; vein M2 well developed; costal ratio
0.55. Halterstembrownish,knob whitish.Abdomendarkbrown.Sternite10with two
pairs of large setae. Two obliquely ovoid spermathecae (Fig. 10) measuring 0.061 x
0.043 mm and 0.054 x 0.033 mm.
Distribution. Argentina and Brazil.
Type. Holotype male, Argentina, Misiones Prov., 2 de Mayo, Salto Encantado,
15-X-1986, C. Roldán, COC light trap (MLPA).
New Record. Brazil, Santa Catarina, Nova Teutonia, IX-1961, F. Plaumann, 1
female (NMNH).
Brachypogon (Isohelea) pallidipennis sp. n.
(Figs. 11-16)
Diagnosis. Oistinguished from all other Neotropical species of Brachypogon
(Isohelea) by the following combination of characters: wing membrane whitish hyaline;
stigma lightbrown,veinsnearlyimperceptible;2nd radial cell minute;veinM2 absent;
male withshortstoutgonocoxitebearingstrongsetae distally;gonostyluswithbilobed
apex;aedeaguswithsublateral,distomedian,andlaterallydirectedprocesses;parameres
fused, quadrate with a pair of mesal, anteriorly directed processes and pair of slender
laterallydirectedprocesses;andfemalewithtwoobliquelyovoidspermathecaeandlong
slender unequal claws, with basal inner teeth.
Female. Wing lenght 0.68 mm; breadth 0.32 mm. Head dark brown. Eyes
contiguous, pubescent. Antennalscapewith4-5setae;flagel1um (Fig. 11)darkbrown,
lengths of flagellomeres in proportion of 28-14-14-14-15-15-15-15-24-24-25-21-27;
antennal ratio 0.93; flagellomere 1 with two apical sensilla coeloconica. Palpus (Fig.
12) brown, lengths of segments in proportion of 17-30-31-20-28;segment3 with deep
round sensorypit, palpal ratio 1.40;palpalsegment4 with two large setae. Mandible
withnineteeth.Thoraxdarkbrown;five prealarsetae;onekatepisternalseta;scutellum
with two marginal and two central setae. Legs dark brown, tibiae lighter brown
subbasallyand apically, tarsi except tarsomeres5pale;hind tibia withcomb of seven
setae, apical spur large and deeply trifurcate; hind tarsal ratio 2.50; tarsomeres 4
subcylindrical; tarsomeres 5 elongate slender with long slender unequal claws with
basal inner teeth, lengths of fore, mid and hind claws in proportion of 12:9, 16:12,
16:12.Wing (Fig. 13)membranewhitishhyaline,stigmaandanteriorveins palebrown,
other veins nearly imperceptible; membrane covered with fine microtrichia,
macrotrichia only on margin and a few on radius; two radial cells, 2nd minute; r-m
crossvein oblique; vein MI and cubitalfork obsolete at ápices. M2 absent; costalratio
0.52. Halter whitish. Abdomen dark brown. Sternite 10 with one pair of large setae.
Two unequal sized, obliquely ovoid spermathecae (Fig. 14) with short conical necks;
measuring 0.064 x 0.051 mm, and 0.051 x 0.028 mm.
SPINELLI,G.R. &W. L. GROGAN, j-, Brachypogon 7
11
13
12
16
Figs. 11-16. Brachypogon(Lsohelea) pallidipennis. 11,female flagellum; 12, female palpus; 13, female
wing; 14, spermathecae; 15,male genitalia, aedeagus removed; 16,aedeagus.
8
Rev.Soco Entomol.Argent. 53 (1-4), 1994
Male. Similar to female with the following notable sexual differences. Eyes
separated. Mandible reduced, vestigial. Katepisternum with six setae. Tarsomeres 4
cylindrical;c1awssmallsimplewithbentbifidtips. Wingnarrower,membranelacking
macrotrichia; wing length 0.64 mm, breadth 0.26 mm; costal ratio 0.49 . Genitalia as
in Figs. 15-16. Sternite 9 moderately long with a shallow caudomedian excavation;
tergite9long, producedbeyondapexofgonocoxite, tip broad;cercishort.Gonocoxite
short, stout, 1.35 x longer than broad, distally with 12stout setae; gonostylus stout,
as long as gonocoxite,surfaceirregular, distal portionslightlycurved, apex with two
stoutsc1erotizedlobes.Aedeagus(Fig.16)triangular;basalarmshort;marginsheavily
sc1erotized, as are the 2 sublateral distally directed processes and a distomedian
process whichextendsbeyond the truncate tip of aedeagus proper; a pair of laterally
directed,stronglysc1erotizedprocessesbornefromthe apexof the sublateralprocesses,
eachabruptIybentat apex. Parameresfused intoasmallheavilysc1erotized quadrate
structure, with a pair of anteriorly directed mesal processes, and slender recurved
laterally directed processes thatextend to outer margin of gonocoxite near its base.
Distribution. Honduras.
Types. Holotype male labeled "Honduras, Comayagua, Comayagua, IX-·1966,
F. S. Blanton"; allotype female labeled "Honduras, Valle, Nacome, 28-V-1964, F. S.
Blanton" (both deposited in NMNH).
Etimology. The specific epithet refers to the whitish hyaline wing membrane.
Discussion. Females of B. (l.) wirthi most closely resemble this new species
because their wings are hyaline, vein M2 is absent, and macrotrichia are present on
mostof themargino However, theydifferfrom this newspeciesin havingequalsized
spermathecae, the radial cells are nearly equal sized, and the stigma is yellowish.
Femalesof B.(I.) misionensis have spermathecaesimilar to this new species, but their
wing is infuscated, vein M2 is well developed, macrotrichia are absent in cell cual
and anal cell, and the antennal ratio is greater. The maleof B.(I.) pallidípennís is the
only species of the subgenus Isoheiea that has a gonostylus with a bilobed apex and
an aedeagus with distal processes.
LITERATURE CITED
BORKENT, A. 1992. A new key to sorne genera of Ceratopogonini in the Holarctic (Diptera:
Ceratopogonidae). Entomol.Scandinavica 22 (1991):433·436.
DOWNJE.SF.,eAt.aJ.l.&(eWds..)W. M. WanIuRaTlHo.f1N9e8a1r.cCtihcaDptieprte2r8a..CVeorla.t1o.pAoggroinei.dCaea.npadpa.3M93o-n4o2g3.r.E2n7:.MOcttAawlpain.e,
GROGAN, W.L.,[r. &A. BORKENT. 1992.Sinhalohelea,anewgenusofpredaceousrnidgeof the
tribeCeratopogoninifrorn Sri Lanka (Diptera:Ceratopogonidae). Proc. Entomol.Soc.Wash.
94:314-319.
SPINELLI,G. R.1990. ThegenusBrachypogonin Argentina,withakeyto theNeotropicalspecies
(Diptera,Ceratopogonidae). Rev.Bras. Entomol.34(4):743-755.
WIRTH, W. W. & W. L. GROGAN, Jr. 1988. The PredaceousMidges of the World (Diptera:
Ceratopogonidae;TribeCeraiopogonini).FloraandFaunaHandbookn°4.E.J.Brill, NewYork,
XV+160pp.
Recibido: 28-IX-1992
Aceptado: 27-XII-1992